BAHIR DAR UNIVERSITY
Ethiopian Institute of Textile
and Fashion Technology
Production Maximization of Open End by optimizing
Rotor Speed
DESIGN OF EXPERIMENT
Cylinder Speed
Twist Level
Submitted to :Million A.(Asst. Professor)
Prepared By :Addisu Temesgen
February 24, 2021
Contents
 Objective
 Introduction
 Materials and Methods
 Results and Discussion
 Response Characterization
 ANOVA For Linear Model
 Response: Production rate kgs/hr.
 Optimized
 Conclusions
 References
Objective
• The study was aimed to maximize the production rate of open-end
machine by optimizing rotor speed, yarn twist and card cylinder speed.
• Or reducing yarn end breakage rate, since end breakage rate has a
direct relation to production rate on 21 Ne yarn.
• To develop a polynomial model by using response surface method to
show the effect of machine parameters and twist on production rate.
Introduction
 open-end spinning principle is significantly acceptable for its high
production rate, processing of short to medium grade cotton and its
capability to processing of waste fibers at relatively lower cost.
 Now a days, rotor spinning system is rising due to the considerable
reduction in space and personnel.
 Sliver-- guided by the feed roller ----opened up by the opening roller ---- removed from the opening roller by air suction through the fiber
transport channel----- twist inserted ------ rotor generates twist.
Cont.…..
 factors which affect the tensile properties of rotor spun yarn cotton:-fiber properties,
yarn properties and machine parameters.
 yarn strength increased with increase of rotor speed, yarn twist and linear density.
1) formation of more wrapping fibers, increased centrifugal force in the spinning region
2) increased fiber interaction.
3) increased fiber in the yarn cross section.
 preparation of the feed material and opening roller speed also affect tensile
properties Rotor speed increases machine productivity and twist reduces the
productivity
.
Cont …. …
 RSM introduces statistically designed experiments for the purpose of
making inferences from data.
A mathematical model equation have to fit in order to approximate a
relationship between response and independent variables
Determine the optimum settings of these variables that result in the
maximum response.
Cont…
The Box–Behnken design provides three levels (-1, 0, +1)
N = 2k (k -1) + C0,
Design is more economical and efficient
Useful in avoiding experiments performed under extreme conditions
 Used finding the optimum experimental conditions, leading to an
optimal efficiency of different processes
Materials and Methods
 A sliver of 0.11 Ne was prepared by Reiter IDF which is integrated with
Reiter card C – 60 machines. With different cylinder speed (i.e., 720,
760, 800 rpm with qualities given in the table.
property
Carded sliver
IDF sliver
Weight [gm]
35.831
26.059
Hank delivered [Ne.]
0.08
0.11
Coefficient of variation
(CV %)
0.98
Input material
Parameters – HVI
Results
UNITS
Measured values
Staple length [UHML]
mm
25.11
Maturity
%
0.84
Uniformity index
%
79.7
Microniar
µg/inch
4.1
Tenacity of fiber bundle
g/Tex)
26.5
trash
%
4.5
moisture content
%
7.5
Waste
%
15
Cont …..
By using Box–Behnken model of RSM the design matrix of the experiment
is designed
 the total observation became fifteen by considering three center point.
 the experimental trial has caried out at % RH= 65 and 26 o c which is in
standard range for open end spinning and to reduce variations due to
experimental trial : the same operator , the same input cotton, the same
machine spindle
Cont …
the sliver was feed to O/E feed roller based on experimental matrix data at
different twist and rotor speed
 the production rate and breakage rate of the rotor is directly taken from
machine screen. These data were taken as the experimental result
No.
Model Type
Name
Actual running speed
1
C - 60
Carding machine
760 rpm [cylinder speed]
2
C - 60
Carding machine
Sliver delivery 86 kg /hr.
3
R923
Open end
90,000 rpm
4
Rotor =33mm, V-shaped
Rotor
90,000 rpm
5
R923
Opening roller
9300 rpm
Table 3. Design Matrix Of 21 Ne. Open End Yarn Productivity
Std
Run
Factor 1
Factor 2
Factor 3
Response 1
A:Cylinder Speed
B:Roter Speed
C:Twist
Production
RPM
RPM
TPM
kgs/hr.
9
1
760
85000
900
0.159
5
2
720
90000
900
0.169
12
3
760
95000
940
0.163
8
4
800
90000
940
0.162
13
5
760
90000
920
0.167
3
6
720
95000
920
0.175
4
7
800
95000
920
0.174
11
8
760
85000
940
0.159
1
9
720
85000
920
0.156
15
10
760
90000
920
0.165
14
11
760
90000
920
0.168
7
12
720
90000
940
0.161
2
13
800
85000
920
0.158
6
14
800
90000
900
0.179
10
15
760
95000
900
0.177
Responses
Respons
e
R1
Name
Units
Observat
Analysis
ions
Minimu
m
Maximu
m
Polynom
ial
0.156
0.179
Producti
kgs/hr.
on
15
Mean
Std. Dev.
0.1661
Ratio
0.0074
Transfor
m
1.15 None
Model
2FI
Factors
Factor
Name
Units
Type
Minimum
Maximum
A
Cylinder
Speed
RPM
Numeric
720.00
800.00
B
Roter
Speed
RPM
Numeric
85000.00
95000.00
C
Twist
TPM
Numeric
900.00
940.00
Coded Low
Coded
High
-1 ↔
720.00
+1 ↔
800.00
-1 ↔
85000.00
+1 ↔
95000.00
-1 ↔
900.00
+1 ↔
940.00
Mean
Std. Dev.
760.00
30.24
90000.00
3779.64
920.00
15.12
Results and discussion
Response Characterization
 The results were analyzed using response surface regression analysis.
 Significancy of model and factors for the experimental design given in
Analysis of variance (ANOVA).
 Response surface regression models estimated for yarn production
rates included both significance and insignificance factors.
ANOVA table For first order Model
The Linear Regression Model of Initial Design
Production = 0.1661 + 0.0015A + 0.0071B - 0.0049 C……… 3
Std. Dev.
0.0037
R²
0.8064
Mean
0.1661
Adjusted R²
0.7536
C.V. %
2.20
Predicted R²
0.5926
Adeq
Precision
12.6926
The Predicted R² of 0.5926 is in reasonable agreement with the Adjusted R² of 0.7536;
i.e. the difference is less than 0.2.
Figure 1. a) actual vs predicted value. B) the effect of variables on open end
Design-Expert® Software
Cube
Predicted
vs. Actual
Factor Coding:
Actual
0.18
Production (kgs/hr.)
Production (kgs/hr.)
X1 = A: Cylinder Speed
X2 = B: Roter Speed
0.166883
X3 = C: Twist
0.169883
0.175
B+: 95000
0.176633
2
0.179633
0.165
B: Roter Speed (RPM)
Predicted
0.17
0.16
0.155
3
0.152633
2
0.155633
0.15
0.15
0.155
0.16
0.165
Actual
0.17
0.175
B-: 85000
C-: 900
0.162383
0.165383
A-: 720
A+: 800
A: Cylinder Speed (RPM)
0.18
C+: 940
C: Twist (TPM)
(kgs/hr.)
Figure 2. response surfaceProduction
graph:
a) show the effect of cylinder speed and rotor speed on production rate
Design points above predicted value
b) The
of predicted
yarn twist
Designeffect
points below
value and cylinder speed on pr. Rate
value
value
0.156
0.179
0.18
0.18
X1 = C: Twist
X2 = A: Cylinder Speed
0.175
0.175
B: Roter Speed = 90000
0.17
Production (kgs/hr.)
Production (kgs/hr.)
Actual Factor
0.165
0.16
0.155
720
740
760
A: Cylinder Speed (RPM)
780
95000
93000
91000
89000
B: Roter Speed (RPM)
87000
800 85000
0.17
0.165
0.16
0.155
800
900
780
910
760
740 A: Cylinder Speed (RPM)
920
C: Twist (TPM)
930
940 720
Figure 3. The graph of main effects on production rate
Linear Regression Model
 The insertion of twist affects yarn production rate negatively as seen
by regression table where as rotor speed increases productivity.
 relative the others, the coefficient of cylinder speed very small which
show its power of effect is low.
Response Optimization
• Since the experimental result showed that cylinder speed has
insignificant effect on the responses . I put the goal as
• production as in target , cylinder speed in range, rotor speed as
maximize, twist level minimized the optimization become effective
with desirability 0.93 gives production rate 0.173 kg/hr. with low
cylinder speed (720 rpm) and rotor speed 92768.3 rpm.
1
Actual Factors
C: Twist = 900
Responses
Desirability = 0.930391
Production (kgs/hr.) = 0.173453
0.8
0.6
0.4
0.2
0
roduction (kgs/hr.)
B: Roter Speed = 92768.5
Desirability
A: Cylinder Speed = 720
0.19
0.18
0.17
0.16
0.15
0.14
95000
93000
91000
89000
720 740 760 780 800
All Responses
87000
Factor Coding: Actual
85000
A: Cylinder Speed (RPM)
B: Roter Speed (RPM)
Design-Expert® Software
C: Twist (TPM)
900 910 920 930 940
Conclusions
1. The second-order model is the most frequently used approximating polynomial
model in RSM. The Box– Behnken is most suited design for optimization and
prediction of data in textile manufacturing
2. In this study the maximum production rate of open-end machine is achieved by
increasing rotor speed and reducing twist.
3. The quality of sliver resulting by the card cylinder speed change has not a direct
effect
on
the
open-
end
production
rate.
REFERENCES
1. Farooq Ahmed Arain, A. T. (2011). Multiple Response Optimization of Rotor Yarn
for Strength, Unevenness,. Fibers and Polymers, 5.
2. Jacquerie Mirembe, J. I. (2017 ). THE EFFECT OF COUNT, TWIST, OPENING
ROLLER. Engineering Technology and Applied Sciences, 10.
3. Kumar, R. S. (2015). Process Management in spinning. Delhi : Taylor & Francis W.
4. MONTGOMERY, D. C. (2013). Design and Analysis. (E. Edition, Ed.) Arizona State
University:
John Wiley & Sons, Inc.
Thank YOU